1. Field of the Invention
The present invention relates to a wire bonding package, and more particularly, to a wire bonding package having a housing and at least a die electrically connected to the housing via a circuit board.
2. Description of the Prior Art
In modern society with developed computer technology, the computer system, which comprises a plurality of integrated circuits, has been utilized in a broad spectrum of fields. For example, household appliances with automatic control systems, mobile communication devices, and personal computers utilize integrated circuits (IC) to perform certain functions. The main body of the IC is a die manufactured by a prior art semiconductor process. The semiconductor process to manufacture the die starts with forming a wafer. Each wafer is divided into a plurality of regions. On each of the regions, many circuits are formed through prior art semiconductor processes. In the end, each processed region on the wafer is sliced to generate a plurality of die. After the required die is obtained, the processed die is electrically connected with a circuit board such as a printed circuit board (PCB) in a specified way. Therefore, the die is capable of acquiring its operating voltage from the PCB for performing a predetermined operation. Generally speaking, the specific way to electrically connect the die with the circuit board includes connecting a bare chip (die) directly to the circuit board, or packaging the die inside a package in advance so that the die is electrically connected to the outer circuit board through a circuit layout within the package for receiving power and transmitting signals.
In recent years, a plurality of mutual supporting die have been integrated into a single package to meet the demand for time-to-market. Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic diagram of a quad flat multi-die wire bonding package 10 having a first die 12 and a second die 14 stacked on the first die 12 according to the prior art. FIG. 2 is a side view of the wire bonding package 10 shown in FIG. 1. The wire bonding package 10 further comprises a plurality of bonding lines 24 and a housing 16 having a plurality of pins 18 installed. Both the first die 12 and the second die 14 comprise a core circuit for executing a predetermined operation and a plurality of input/output circuits for processing data accessed to/from the core circuit. The first die 12, and the second die 14 as well, further comprises a plurality of die pads 20, 22 for connecting to the pins 18 of the housing 16 via the bonding lines 24.
Usually, before being stacked together and installed inside the housing 16, the first die 12 and the second die 14 have to be re-designed to eliminate a bonding line crossing problem, for example a bonding line 74 connecting a die pad 84 and a pin 94 crossing a bonding line 72 connecting a die pad 82 and a pin 92 as indicated by arrow A, and crossing a bonding line 70 connecting a die pad 80 and a pin 90 as indicated by arrow B. However, the re-resign necessity of the first die 12 and the second die 14 complicates the demand for time-to-market.
Moreover, even if both the first die 12 and the second die 14 have been re-designed before being installed inside the housing 16 and do not have the bonding line crossing problem any more, as the circuits (for example the core circuit and the input/output circuit) inside the die are becoming more and more complicated and the capacity of the housing and the die as well are becoming smaller and smaller, data transmitted over the bonding line 72 connected between the pin 92 of the housing 16 and the die pad 82 of the first die 12 is likely interfered with by data transmitted over the bonding line 70 connected between the pin 90 of the housing 16 and the die pad 80 of the first die 12 due to a coupling effect resulting from the bonding lines 70 and 72 being too crowded. Therefore, the performance of the wire bonding package 10 is reduced, especially when the data transmitted over the bonding line 72 is analog data.